1. Field of the Invention
The present invention relates to a washing machine, and more particularly to a washing machine which pumps a washing liquid towards an upper portion of a spin tub while a washing cycle is being executed, thereby generating a turbulent flow in the spin tub.
2. Prior Arts
Generally, a washing machine is an appliance for separating dirt from articles to be washed such as clothing by sequentially carrying out various cycles in the order of liquid feeding, washing, rinsing, dehydrating, and draining cycles.
While the above cycles are being executed, dirt contained in the articles separates from the articles by means of detergents or by means of friction between the washing liquid and the articles.
However, in conventional washing machines, concentric swirl-shaped liquid flows are generated in a spin tub, so the articles flowing along the concentric swirl-shaped liquid flows become tangled with each other. In addition, the swirl-shaped liquid flows generated from a bottom of the spin tub become weak as they reach an upper portion of the spin tub due to an interference by the articles. For this reason, the washing effect at the upper portion of the spin tub is reduced.
In order to solve the above problem, another conventional washing machine which pumps a washing liquid toward an upper portion of a spin tub while a washing cycle is being executed, thereby preventing the articles from tangling and improving the washing effect, is suggested. U.S. Pat. No. 4,402,198 issued to Cartier discloses one such washing machine.
FIGS. 4 and 5 show Cartier's washing machine 10.
As shown in FIG. 4, Cartier's washing machine 10 includes a cabinet 12. Cabinet 12 has a top 14 with a lid 16 and a console 18 having presettable controls 20 thereon. Lid 16 in top 14 of cabinet 12 permits access into an outer tub 22. Enclosed and supported within outer tub 22 is a spin tub 24 in which an agitator 25 is mounted.
Below outer tub 22, but within cabinet 12, there is provided an electric motor 28 which oscillatably drives agitator 26 through a transmission 30.
FIG. 5 is a sectional view showing an internal structure of agitator 26. As shown in FIG. 5, agitator 26 has a skirt portion 32 near the bottom thereof and a substantially vertical barrel portion 34 integrally connected with skirt portion 32 and projecting upwardly therefrom. A plurality of vanes 36 are provided around a periphery of barrel 34. Vanes 36 extend downwardly and outwardly along skirt portion 32 of agitator 26.
Agitator 26 is of a two-wall construction having an outer wall 40 and a radially inwardly spaced inner wall 41. An annular space 46 is formed between outer wall 40 and inner wall 41. In addition, a channel 42, into which the washing liquid is introduced when agitator 26 rotates, is formed in skirt portion 32.
A chamber 58 is formed at an upper portion of barrel portion 34. A filtering means 60 is detachably secured within chamber 58. Chamber 58 communicates with annular space 46 by an opening 72. In addition, a plurality of apertures 76 are provided at a terminal end of vertical barrel 34.
In a washing cycle, when a user pushes controls 20 installed on console table 18, a microcomputer (not shown) accommodated in washing machine 10 sends an operating signal to electric motor 28 so that electric motor 28 rotates. The rotational force of electric motor 28 is transferred to agitator 26 through transmission 30, so agitator 26 rotates.
As agitator 26 rotates, the washing liquid is introduced through channel 42 formed in skirt portion 32 into annular space 46 formed between outer wall 30 and inner wall 41.
As agitator 26 continues to rotate, the washing liquid flows into chamber 58 through opening 72. Then, the washing liquid which has flowed into chamber 58 passes through filtering means 60 and pumps towards the upper portion of outer tub 22 through apertures 76 formed at the distal end of vertical barrel 34.
In this manner, Cartier's washing machine 10 pumps the washing liquid towards the upper portion of outer tub 22, so a turbulent liquid flow is generated in outer tub 22 and thereby, the washing effect is improved.
However, in Cartier's washing machine 10, agitator 26 has a complicated structure, so the manufacturing of agitator 26 is very difficult.
Further, since the washing liquid pumps towards the upper portion of outer tub 22 through relatively small apertures 76, the washing liquid does not strongly collide with the articles. For this reason, the washing efficiency is relatively reduced.